Weight Loss & Metabolic
Retatrutide
Also known as: LY3437943; sold under the retail label GLP-R
An investigational once-weekly injection that activates three receptors (GIP, GLP-1 and glucagon), still in clinical trials and not an approved medicine.
Overview
Retatrutide is an experimental peptide that activates three receptors at once: GIP and GLP-1, which tirzepatide also targets, and the glucagon receptor, which is thought to increase energy expenditure. It is given by weekly injection in trials.
What the research has looked at
A published phase 2 trial in adults with obesity reported large average weight loss compared with placebo over the trial period, with results rising with dose. Further trials are examining obesity, type 2 diabetes, liver disease and other conditions. The sponsor's phase 3 program is the main source of future evidence.
Safety and limits
- Reported side effects in the phase 2 trial were mostly gastrointestinal and increased with dose.
- Increases in heart rate were also observed.
- Long-term safety and effectiveness have not been established, and results depend on the final phase 3 data.
- Material sold outside clinical trials is not manufactured under regulatory oversight, so its content and purity are uncertain.
Regulatory context
Retatrutide is not an approved medicine. Readers should check current regulatory status.
Related pages
See also Tirzepatide and Cagrilintide.
References & further reading
- Jastreboff AM, et al. Triple-hormone-receptor agonist retatrutide for obesity: a phase 2 trial. N Engl J Med. 2023;389(6):514-526.
Educational reference only. Not medical advice. This page does not recommend or describe human use, dosing or sourcing.